Salmon often jump waterfalls to reach their breeding grounds.
starting downstream, 2.9 m away from a waterfall 0.436 m in height, at what minimum speed must a salmon jumping at an angle of 44.7◦ leave the water to continue upstream? the acceleration due to gravity is 9.81 m/s2 .

5.79 m/s

Explanation:

R=2.9 m

H=0.436 m

∅=44.7°

For Horizontal Motion

aₓ=0      uₓ=ucos∅

x=uₓt+

R=ucos∅*t+0

2.9=ucos(38.3)*t

t=

For Vertical Motion

Y=Uy*t+

By putting value

0.436=usin∅()-()

0.436=sin(44.7)()-()

0.436=2.869-

u²=33.54

u=5.79 m/s

5.83 m/s

Explanation:

This is a projectile motion problem.

Let's call

the initial velocity

In x-coordinate:

where α is 44.7°

In y-coordinate:

In x-coordinate the displacement is:

where t is time. Isolating the initial speed and replacing with x = 2.9 (the distance travelled in x direction) :

In y-coordinate the displacement is:

Replacing with the initial velocity, y = 0.436, alpha = 44.7° and g = 9.81:

Replacing this value in the previous initial velocity equation:

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

i think the answer is a, hope this is right, that would be my best guess.